Support is requested for preparation of a monograph on the applications of biotechnology to health problems in developing countries. The significant technologies, including molecular biology and immunologic methods offer promise of dramatic and perhaps fruitful new approaches to prevention, diagnosis, and treatment of many microbial and parasitic diseases. Nucleic acid hybridization techniques in identifying etiologic agents of diarrheal disease; recombinant DNA methodologies may yield subunit vaccines against a wide range of microbial and parasitic agents; and active drugs conjugated to monoclonal antibodies may be targeted to highly specific sites (including parasite tissues) within the body. Even if reagents are developed that are appropriate, safe, and effective in the laboratory, many more issues may need to be faced before such materials are widely adopted for use in the fields. For example, measles vaccine, active against a relatively simple and invariant virus, has met such criteria for more than 20 years but millions of children in developing countries still die of measles. Materials devised to protect against protozoan and helminthic parasites will be far more rigorously challenged in the field. The proposed monograph will discuss the biologic, epidemiologic, logistic, administrative, economic, ethical and political background in developing countries against which biotechnology-based diagnostic, prophylactic, and curative health measures are to be employed. Special attention will be given to field trials, implementation, and evaluation. Data will be obtained primarily through literature search, interview, and study of reports in archives of relevant organizations.